l66 UNIVERSITY OF MISSOURI STUDIES [3I4 



Plains about Boulder, especially on the banks of irrigation 

 ditches, 5100-6000 ft. (Daniels, 391). 



Missouri to South Dakota and Colorado; Alabama to 

 Arizona. 



271. POINSETTIA Graham. 



674. P. cuphosperma (Engelm.) Small [Euphorbia cuphos- 

 perma _ Boiss.]. Warty spurge. 



Plains east of Boulder and along railroads, 5100-6000 ft. 

 (Daniels, 692). Tenth Street, Boulder (Cockerell). 



South Dakota to Wyoming ; Texas to Arizona and Mex- 

 ico. 



675. P. dentata (Michx.) Small [Euphorbia dentataMichx.] . 

 Toothed spurge. 



On the plains and mesas, frequent, 5100-6000 ft. (Daniels, 



430- 



Pennsylvania to South Dakota ; Louisiana to Utah and 

 Mexico. 



Family 66. CALLITRICHACEAE Lindl. Water starwort 

 family. 



272. CALLITRICHE L. Water starwort. 



676. C. palustris L. Marsh water starwort. 



Aspen bog, Glacier Lake; also in streams and ponds about 

 Boulder, 5100-9000 ft. (Daniels, 248). Eldora lake (W. W. 

 Robbins). 



Nova Scotia to British Columbia; Florida to Califor- 

 nia: Europe: Asia: South America. 



677. C. bifida (L.) Morong [C. autumnalis L.]. Autumnal 

 water starwort. 



South Boulder creek, Arapahoe Road, common ; in com- 

 pany with the preceding species, but more abuncant, 5200-5400 

 ft. (Daniels, 738). Not in Rydberg's Flora. 



Quebec to Manitoba and Oregon ; Michigan to Colorado. 



